If someone has already accepted their gambling addiction and managed to stop gambling, it is synonymous with willpower.
But the paradox is that if you have the strength and conviction to stop gambling, anyone could come to the conclusion: "Why not just control it and that's it, without needing to quit gambling completely?".
Which brings us to this questions:
Is it harder to control gambling or limit it without falling into excess than to stop gambling forever?
Why is the effective strategy not moderation but absolute abstinence?
There is a temptation. For some people, gambling is a temptation. What happens when you are on a diet and smell a very delicious Doner Kebab? You immediately want to eat it and cheat on your diet. Gambling is like that for those, who are addicted to it. There are people who gamble for fun, control themselves and have willpower to not let themselves deep dive into the addiction but there are those who find it very difficult, failed into it and now prefer to not gamble forever cause if they start it, those emotions will revive into them and they'll become addicted again.